irreversible

American  

[ir-i-vur-suh-buhl] / ˌɪr ɪˈvɜr sə bəl /

adjective

1. not reversible; incapable of being changed.

   His refusal is irreversible.

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irreversible British  

/ ˌɪrɪˈvɜːsəbəl /

adjective

1. not able to be reversed

   the irreversible flow of time

2. not able to be revoked or repealed; irrevocable

3. chem physics capable of changing or producing a change in one direction only

   an irreversible reaction

4. thermodynamics (of a change, process, etc) occurring through a number of intermediate states that are not all in thermodynamic equilibrium

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Other Word Forms

• irreversibility noun
• irreversibleness noun
• irreversibly adverb

Etymology

Origin of irreversible

First recorded in 1620–30; ir- ² + reversible

Example Sentences

According to the charity SMA UK, the drug delivers a healthy copy of the affected gene to the body, but timing is critical because irreversible damage may have already occurred in the nervous system.

From BBC

He also met with Chinese Premier Li Qiang on Tuesday, hailing improving ties as the "irreversible trend of the times".

From Barron's

It is caused by the deterioration of of the optic nerve and causes progressive and irreversible sight loss in both eyes.

From BBC

Would it be an affirmation of nature’s power of renewal or an omen of irreversible decline?

From Los Angeles Times

Even if the challengers ultimately prevail and obtain a final legal judgment that the deportation policy is illegal, the deportations that have occurred in the meantime may be irreversible.

From The Wall Street Journal

Related Words

• inevitable
• permanent